To determine the effectiveness of workplace interventions and the most effective methodological design for the improvement of employee productivity, work ability, and absenteeism. A meta-analysis of randomized controlled trials (RCTs) of workplace interventions was conducted (PROSPERO, CRD42018094083). The PubMed, Scopus, PsycINFO, and Cochrane databases were searched. RCTs from 2000 to 2017 and with employees (18-65 years) were selected. Then, intervention characteristics and work-related outcomes data were extracted. A total of 47 RCTs were included in the systematic review, and 19 RCTs (11 absenteeism, 7 productivity, and 5 work ability) were included in the meta-analysis. The meta-analysis showed that the effectiveness of workplace interventions for absenteeism was −1.56 (95% CI, −2.67 to −0.44) and −2.65 (95% CI, −4.49 to −0.81) considering only moderate quality RCTs. In contrast, only a few studies of workplace interventions for productivity and work ability were included, which was insufficient for determining the effectiveness and best design for improving these work outcomes. The workplace is an interesting environment to reduce absenteeism, and individualized and counseling interventions with <10 sessions/total were the most effective workplace intervention methodological design for reducing the absenteeism of employees. Future high-quality RCTs that also consider health risks should be implemented to strengthen the results. 2 of 26 specific task) and their effectiveness (the objectives achieved and problems solved) [5]. In some studies, productivity represents the maximum individual potential performance at employees' workplace [5]. Absenteeism is defined as the time that an employee is away from work due to illness or disability [2]. In contrast, presenteeism is defined as performing work at a lower level than usual during work time, with presenteeism problems not necessarily leading to absenteeism [2]. Consequently, both absenteeism and presenteeism could decrease the productivity of employees [2]. Additionally, another analyzed work-related aspect is work ability. Work ability has two definitions, namely, one definition for specific jobs that require special training, and one definition for jobs that most people can manage given a short period of practice [6].The workplace is an excellent context for improving health outcomes because employees spend a substantial part of their days there [1]. Additionally, employers not only are responsible for providing a safe and hazard-free workplace but also have opportunities to promote and foster a healthy work environment [7]. As an extra benefit, the maintenance of a healthy lifestyle among employees reduces the direct and indirect costs [7]. Another interesting focus concerns the effects of workplace interventions on employee health lifestyle outcomes, such as physical activity, nutrition, weight reduction, or stress management [8,9], whereas it has not been defined how these lifestyle health aspects can contribute to improved work-related outcomes [10]. A ...